Old ceremonial masks and knives are popular symbols of pre-Hispanic Peruvian culture. Examples adorn the covers of books on Peru and serve as emblems for some Peruvian institutions. These precious metal artifacts are often attributed, even by knowledgeable persons, to the Incas or to their coastal rivals, the Chimú. Yet many of them are not Incan or Chimú at all: they were created much earlier by the Sicán culture, which was centered in the Lambayeque region of northern Peru and flourished from the ninth to the 14th centuries.

The Middle Sicán era, between 900 and 1100 C.E., produced enormous quantities of precious metal artifacts, many showing extraordinarily high craftsmanship. We and our colleagues from several disciplines have scrutinized the metalwork from one Middle Sicán trove in an attempt to reconstruct the technology and organization of precious metal production and to define the meaning of those products within the culture. We determined that the scale and the range of metal use by the people of the Middle Sicán was unprecedented in the pre-Hispanic New World. That culture's extensive production of arsenical copper ushered the bronze age into northern Peru. Gold alloys were the most prestigious media for political, social and religious expression. In fact, we suspect that metallurgical production was a prime mover of Middle Sicán cultural developments.

Ambiguity and ignorance have traditionally shrouded precious metal artifacts of the Middle Sicán. Almost all of those in private and public collections were looted from tombs within what is today the Poma National Historical Sanctuary in the mid-La Leche Valley, about 800 kilometers north of Lima. The modern period of intensive grave robbery began in the 1930s. Treasure hunters sank vertical prospecting pits into likely spots, then dug horizontal tunnels outward. With the discoveries of more rich tombs, the extent of the looting continued to increase through the 1940s and 1950s. It culminated in the late 1960s, when a bulldozer was employed for a year to remove the surface soil so that outlines of the tomb pits could be seen more easily. Looting took place sporadically until the mid-1970s, effectively hindering any long-term scientific study of the regional prehistory. When one of us (Shimada) began fieldwork in 1978, he counted more than 100,000 looters' holes and hundreds of long bulldozer trenches on aerial photographs of the Poma sanctuary.

The lack of contextual information for those looted artifacts greatly limits understanding of their sociopolitical, religious and economic significance. Moreover, looters and collectors often took questionable and undocumented measures to "restore" stolen artifacts. Pigments, feathers and ancient tool marks on gold objects could have been removed by careless cleaning. "Missing" inlay pieces or bangles were often arbitrarily replaced. As a result, the appearance of objects cannot be taken at face value, which limits the information that can be drawn from them. Any attempt to understand the objects, their cultural significance and the techniques used in their manufacture is therefore best founded on those artifacts scientifically recovered from intact tombs.

Sampling a Tomb
THE OPPORTUNITY to gain just such an understanding came about with the first scientific excavation of the tomb of a member of the Middle Sicán elite at Huaca Loro, an adobe platform mound in the Poma sanctuary. The tomb was apparently one of a string left by the Middle Sicán, some of which had already been looted, along the east and south bases of Huaca Loro. Shimada recognized it during a survey of Batn Grande in 1978. He planned its excavation over the next 10 years as part of his broader sampling of Sicán tombs for the elucidation of that culture's social organization. Preparations included assembling a group of specialists and piecing together a Sicán cultural chronology, as well as the performance of other background research.